منابع مشابه
Johannes Holtfreter (1901-1992)
Johannes Holtfreter [6] made important discoveries about the properties of the organizer [7] discovered by Hans Spemann [8]. Although he spent much time away from the lab over many years, he was a productive researcher. His colleagues noted that the time he spent away helped revitalize his ideas. He is credited with the development of a balanced salt medium to allow embryos to develop; the disc...
متن کاملHoyle–Lyttleton Accretion onto Accretion Disks
We investigate Hoyle–Lyttleton accretion for the case where the central source is a luminous accretion disk. In classical Hoyle-Lyttleton accretion onto a “spherical” source, accretion takes place in an axially symmetric manner around a so-called accretion axis. In the spherical case the accretion rate Ṁ is given as ṀHL(1− Γ), where ṀHL is the accretion rate of the classical Hoyle–Lyttleton acc...
متن کاملVolker Kaibel and Rafael Mechtel
We introduce revlex-initial 0/1-polytopes as the convex hulls of reverse-lexicographically initial subsets of 0/1-vectors. These polytopes are special knapsack-polytopes. It turns out that they have remarkable extremal properties. In particular, we use these polytopes in order to prove that the minimum numbers gnfac(d, n) of facets and the minimum average degree gavdeg(d, n) of the graph of a d...
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ژورنال
عنوان ژورنال: American Antiquity
سال: 1968
ISSN: 0002-7316,2325-5064
DOI: 10.1017/s0002731600091678